For this tutorial, since we will be deploying the platform on Linux VMs, I am going to assume that we are going to install everything from a Linux command line exclusively, using our cross-platform CLI tools and the Management Portal Web interface when required. In other words: you don't need a Windows machine to follow this tutorial ;-)

In summary, here are the steps that we are going to follow:

Preparing our SSH keys for authentication on the cluster

Creating the Virtual Network that defines which internal IP addresses the VMs will use

Creating our VMs

Configuring the DNS so that all machines can resolve their internal names and IP addresses

Run the Cloudera Manager installer to create the Hadoop cluster

I hope you enjoy this document, and please send feedback!

Preparing our SSH keys

First, let's create an SSH key and certificate to use for authentication. This will be useful in order to log on to all our VMs without being prompted for passwords. You can find a more detailed SSH procedure in the Windows Azure documentation for Linux Virtual Machines. This is slightly different from what you would do usually to generate new SSH keys (i.e., use ssh-keygen).

$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout myPrivateKey.key -out myCert.pem
Generating a 2048 bit RSA private key
....+++
.......................................................+++
writing new private key to 'myPrivateKey.key'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:FR
State or Province Name (full name) [Some-State]:92
Locality Name (eg, city) []:Issy-les-Moulineaux
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Microsoft
Organizational Unit Name (eg, section) []:DPE
Common Name (e.g. server FQDN or YOUR name) []:Thomas Conte
Email Address []:tconte@microsoft.com

Windows Azure needs the SSH public key to be embedded in a PEM formatted certificate, but you could enter any information you want, it doesn't matter. It's only the generated public key we are interested in!

Let's secure the key and move it to our .ssh directory so that it used by default.

$ chmod 600 myPrivateKey.key
$ mv myPrivateKey.key ~/.ssh/id_rsa

I have found that Cloudera Manager does not like the private key format very much though. Let's convert it right now and keep the generated file somewhere, we will need it later:

$ openssl rsa -in ~/.ssh/id_rsa -out PrivateKeyCDH

Creating the Virtual Network

We will use the cross-platform command-line tools to create our VMs. If you haven't got them installed, first go through the steps to install the Windows Azure Command-Line Tools for Mac and Linux. I won't go into the details here, but once installed you should be able to type azure from the command line and get a friendly response back, plus you must import your publish settings so that the CLI is connected to your Windows Azure subscription.

Update: you can now create a Virtual Network using the command-line tool.

Read on if you want to understand more about the Virtual Network configuration, otherwise you can just skip to the next step!

The first thing we need to create is an Affinity Group, a kind of alias that will represent the datacenter where all our infrastructure will be created. In the Portal, on the left-hand side, at the bottom of the menu, click on Settings, then click on the Affinity Groups tab at the top of the main area. Click on Add an Affinity group, give it a name (I will use "cdh-AG") and select the datacenter (I will use North Europe).

The simplest way to create a complete Virtual Network configuration is to import a ready-made configuration file. Here is the one I used, you can save it into a file and edit it as needed. It is also possible to create a Virtual Network "manually" from the Portal and then export this configuration to a file to inspect or modify it (see Annex 1).

If you look at the XML configuration file below, you will find the following information:

The Virtual Network name, cdh, and the Affinity Group where it will be created, cdh-AG

The address space that will be used to assign IP addresses to the Virtual Machines (10.0.0.0/20)

Within this address space, one or several subnets the VMs will be deployed in, 10.0.0.0/23, each being given a name that you can use when configuring the Virtual Machines (Subnet-1)

The IP address of a DNS server (more about this below), which of course resides within the address space of the Virtual Network, i.e. 10.0.0.4 in this case

A reference from the Virtual Network to the DNS server: all VMs will get assigned this DNS when they request their network configuration from Windows Azure

The trick here is: how did I choose 10.0.0.4 as the address of the DNS server? I know by experience that Windows Azure will allocate IP addresses sequentially within the Subnet, and that in this case, the first one it will allocate is 10.0.0.4. In short, this means that the first VM I start will become the DNS for the rest of the machines in the Virtual Network.

This is really a shortcut, and the longer way is to create the Virtual Network in the Portal, start the first VM, make a note of its IP address, and then register it as a DNS using New, Networks, Virtual Network, Register DNS Server. Importing the configuration file is just a faster way to get everything configured!

Make sure you use your Affinity Group name in the AffinityGroup attribute of the VirtualNetworkSite element!

To import this configuration, in the Portal, go to New, Networks, Virtual Network, and select Import Configuration. The Virtual Network will be created and will then appear in the Networks module in the Portal.

Creating our Admin/DNS VM

We will prepare a Storage Account in our new Affinity Group, where the Virtual Machine disks will be stored. We can do this from the command line:

$ azure account storage create --affinity-group cdh-AG cdhstorage

Now let's find a good Linux image to use. You can use the following command to list all current images.

Now let's create our first VM. This VM will become our DNS server and will also be used to run the Cloudera Manager. For this first step we ask for a "small" size since we don't need to run much stuff. We specify that we want to open the SSH port for remote shell, and add our SSH certificate so that the VM is properly setup for authentication. We also specify our Virtual Network and Subnet so that the VM gets assigned an IP address from the prefix we selected. Finally, we need to specify the Affinity Group, obviously the same we used when creating the Virtual Network.

As you can see, the internal IP address assigned to your VM is indeed 10.0.0.4, and thus will be used as DNS server by all the VMs we will create next. Now let's turn this VM into an actual DNS!

You can now ssh into your new VM, if your SSH configuration is correct you should be able to log in without a password prompt. Otherwise just make sure you correctly copied your private key file into your .ssh directory.

Configuring the DNS using BIND

Now if you look at your DNS configuration, you should see something like this:

This is fine, however in order to install our DNS we need to be able to resolve names until we have installed BIND on our VM! For now, temporarily comment out 10.0.0.4 and use a public DNS:

#nameserver 10.0.0.4
nameserver 8.8.8.8

Now you should have DNS resolution in order to run apt-get and install BIND:

# apt-get install bind9
# /usr/sbin/named

Now that BIND is running, you should be able to switch your DNS back to 10.0.0.4 in /etc/resolv.conf.

We are going to configure BIND in order to resolve our host names. We don't need a real domain, as this name resolution will only take place within the bounds of our deployment; I am going to use a fake TLD, "internal", and setup the forward and reverse zone files.

Now you should run a few tests using nslookup to make sure everything is in order, e.g. the forward and reverse resolutions work.

To make BIND re-read its configuration file, find its PID using ps aux or in /var/run/named/named.pid, and send it a SIGHUP signal, i.e. kill -HUP (pid).

Initializing the cluster

We are now ready to create more virtual machines! These will be the actual nodes in our Hadoop cluster, and we will name them with numeric suffixes so that we can identify them easily. We will use a similar command line as above, except we are going to request larger intance sizes.

You can quickly create four instances from the Bash prompt using a mini-script like this:

These are the name and addresses that we will add to our BIND configuration in order to resolve all the names and addresses.

We are then going to add some additional storage, for my test I will use 150GB drives, however you could use as much as 1TB per disk, and even add several of these disks to each machine if you need even more storage.

$ for i in 1 2 3 4; do
> azure vm disk attach-new mycdh-$i 150
> done

Now we are going to switch to the first machine we created, our "admin" machine, to further configure our new VMs. Let's copy our SSH key over so that we can connect to all other VMs from our first one:

$ scp ~/.ssh/id_rsa mycdh.cloudapp.net:.ssh/

Once logged on our admin machine, let's add the IP addresses of our nodes to BIND's configuration (use kill -HUP again on the named process to force BIND to re-read its configuration files).

In db.internal:

mycdh-1 IN A 10.0.0.5
mycdh-2 IN A 10.0.0.6
mycdh-3 IN A 10.0.0.7
mycdh-4 IN A 10.0.0.8

To make things easier, you can also add the following line to /etc/resolv.conf in order to make "internal" the default domain searched, so that you don't have to type the complete name each time:

search internal

You should now be able to log on to all three other VMs using their FQDN, this will initialize the SSH trust and make sure you can connect without being prompted for a password.

$ ssh mycdh-1
$ ssh mycdh-2
$ ssh mycdh-3
$ ssh mycdh-4

Now we have to make it so we can run commands on all nodes as root via sudo. We are going to overwrite the configuration created by the Windows Azure Agent at first boot (/usr/sbin/waagent) to make sure we can sudo without a password. Of course you should replace the account there by the account you created when you ran the azure vm create commands. First on our admin machine:

Now you can run commands as root without ever being prompted for a password. What really happens is that you ssh implicitly using your current user name ("tom" in my case), since it exists on all machines. You can then execute "sudo" via ssh, and pass it a command to execute as root in turn, e.g.:

$ ssh tomcdh-2 sudo id

If you get warnings from sudo about not being able to resolve host names, you need to add the "search" option to resolv.conf on the other machines as well:

You will then need to partition, format and mount the new disk on every machine. You can easily log in as root using:

$ ssh -t mycdh-1 sudo -i

And then use the following shell snippet. It will partition with sfdisk the Windows Azure volume that you attached previously using azure vm disk attach-new, format it, add it to fstab, and finally mount it on /data.

You should now see the beautiful retro-vintage text-based Cloudera Manager installation screen! Accept (and read) all the licenses, then the installation will proceed and, if everything goes well, you will be presented with the following success screen.

As instructed, we need to connect to the Web application on port 7180. Since we are running on a server VM, we don't have a browser we can launch to open localhost, so let's instead open the port to the outside world:

$ azure vm endpoint create mycdh 7180

Note :this currently fails in the CLI, see Issue #543. For now we have to use the Portal to create endpoints on VMs that are part of a Virtual Network.

In the Management Portal, go to the Virtual Machines module, and select your admin VM in the list ("mycdh" in my case), then go to the Endpoints tab. You should see a rule fort TCP port 22 (SSH). On the dialog that appears, select Add Endpoint, click Next, then give a name to your new endpoint (e.g. "ClouderaManager"), and enter 7180 for the Public and Private port fields. The new rule should now appear in the list of Endpoints.

Now you can connect to the Cloudera Manager interface using the external URL for your admin machine (e.g. in my case, http://mycdh.cloudapp.net:7180/) and start the Web-based installation wizard.

Using the Cloudera Manager to deploy the Hadoop cluster

On the "Thank you" screen, click Continue.

On the "Specify hosts", use the following pattern to describe your hosts:

mycdh-[1-4].internal

You need to specify the FQDN, otherwise you will run into problems later when the JobTracker looks up the IP address for validation: the reverse lookup must exactly match the hostname used.

On the first "Cluster Installation" screen, I removed Impala but otherwise I left all the other options by default.

On the "SSH credentials" screen, you will need to check "Another user" and enter the username used to log on your VMs. You will also need to check "All hosts accept same private key" and provide the key we generated above. I run Cygwin on my Windows machine and I used this command to copy the key from my Linux workstation in Windows Azure to C:\TEMP:

On the "Installation in progress" screen, everything should install successfully. If you encounter SSH credentials issue, this screen will help you troubleshoot the problem.

The next screen will install all the selected parcels to your machines.

On the "Host inspection" screen, everything should be green! Pay special attention to host name resolution warnings at this stage, they may cause problems later if they are not resolved now.

On the "CDH4 services" screen, choose the services you want to install. I will choose "Core with Real-Time Delivery" for a base Hadoop stack plus HBase. If you want to fine-tune which services will run on which hosts, you can click on "Inspect Role Assignments" to check what will run where. You will see that the first machine gets a larger share of services, and in production you might want to make it a larger instance size.

On the "Database setup" screen I kept the Embedded Database, then clicked on Test Connection, then Continue.

When you reach the "Review configuration changes" page, remove the /mnt/resource disk from all nodes running the HDFS service (this is a local, non-persistent disk and we don't want to store data on it). You will also need to lower the tolerance accordingly (i.e. set it to 0 in this case). Likewise for the NameNode and MapReduce services, remove all occurences of /mnt/resource.

That's it! All the services should start successfully. Congratulations!

Accessing the Hue Web UI

Now you may want to access the nice Web UI that Cloudera integrates in their distribution. On the main Services page, click on "hue1" and you will see a status page where you will find a "Hue Web UI" button. Press it, and it should fail! The management portal redirects you to the internal address of the Hue node, e.g. http://mycdh-1.internal:8888/, and this address is not known from the outside world. You should use the corresponding public address, i.e. mycdh-1.cloudapp.net in my case, and open the port (8888) by creating an endpoint in the Windows Azure Management Portal. You can proceed in the same manner whenever you need to access a service directly on one of the nodes.

Annex 1: Manually creating a Virtual Network

Connect to your Windows Azure management portal, and select New, Networks, Virtual Network, Quick Create, and just select a name and a location (data center) for your Virtual Network; all our VMs will later be created in the data center you select. You can also select the size and the address prefix, I will just go for the defaults.

Once the Virtual Network is created, click on its name and then on Dashboard to see how it was configured. You will see that an Affinity Group was automatically created, for example if you named your Virtual Network "cdh" if will be associated with a "cdh-AG" Affinity Group. Now if you click on Configure, you will find another important piece of information: a Subnet was automatically created for you, typically named "Subnet-1" if you went for the Quick Create defaults. We will need these two parameters later to create our Virtual Machines.